BSFS Bachelor of Science in Forensic Science 4 — Questions and Answers
Question 1: Which reagent is commonly used at crime scenes to detect latent bloodstains on surfaces that have been cleaned?
- Luminol (Correct answer)
- Ninhydrin
- Sudan Black
- Coomassie Blue
Correct answer: Luminol
Luminol reacts with the iron in hemoglobin to produce chemiluminescence, revealing traces of blood even after a surface has been cleaned.
Question 2: In forensic entomology, what is the 'minimum postmortem interval' (mPMI)?
- The shortest possible time between burial and discovery
- The earliest time since death indicated by insect activity on a body (Correct answer)
- The minimum time required for a full autopsy
- The earliest time a toxicology report can be completed
Correct answer: The earliest time since death indicated by insect activity on a body
The minimum postmortem interval is the earliest estimated time of death based on the most developed stage of insect found on a body.
Question 3: What is the significance of the Daubert standard in US forensic science?
- It sets chain of custody requirements for biological evidence
- It establishes criteria for judges to evaluate the admissibility of scientific expert testimony (Correct answer)
- It mandates accreditation for forensic laboratories
- It defines the rights of suspects during evidence collection
Correct answer: It establishes criteria for judges to evaluate the admissibility of scientific expert testimony
The Daubert standard, established by the Supreme Court in 1993, requires judges to act as gatekeepers evaluating scientific testimony based on factors like peer review, error rate, and general acceptance.
Question 4: Which type of glass fracture pattern indicates the direction of force applied?
- Hackle marks on the glass edge
- Concentric fractures around the impact point
- Radial fractures extending outward from the impact
- All of the above contribute to directionality analysis (Correct answer)
Correct answer: All of the above contribute to directionality analysis
Forensic glass analysis uses radial and concentric fracture patterns together with hackle marks and rib marks to determine the direction and sequence of impacts.
Question 5: What analytical technique is most appropriate for comparing paint chips recovered from a hit-and-run vehicle?
- Polarized light microscopy and scanning electron microscopy with EDX (Correct answer)
- Only visual color comparison
- Fingerprint powder analysis
- Gas chromatography alone
Correct answer: Polarized light microscopy and scanning electron microscopy with EDX
Polarized light microscopy examines layer structure, while SEM-EDX provides elemental composition of paint pigments, allowing detailed comparison of paint chip samples.
Question 6: In forensic odontology, what is the primary application of bite mark analysis?
- Determining age of the victim from dental wear
- Comparing bite mark patterns on skin or food to a suspect's dentition (Correct answer)
- Reconstructing facial features from skull remains
- Identifying drug use through enamel erosion patterns
Correct answer: Comparing bite mark patterns on skin or food to a suspect's dentition
Bite mark analysis involves comparing the unique pattern of a bite mark found at a crime scene or on a victim to dental impressions taken from a suspect.
Question 7: What is a 'stippling' pattern in a gunshot wound, and what does it indicate?
- A star-shaped exit wound indicating high-velocity rounds
- Scattered abrasions from burning gunpowder particles embedded in skin, indicating intermediate range fire (Correct answer)
- Bruising around entry wound from a contact shot
- Tattoo-like marks from repeated non-fatal shots
Correct answer: Scattered abrasions from burning gunpowder particles embedded in skin, indicating intermediate range fire
Stippling (also called tattooing) consists of small abrasions caused by unburned and partially burned gunpowder striking skin, typically seen at intermediate firing ranges of 6-48 inches.
BSFS Bachelor of Science in Forensic Science 4
Which reagent is commonly used at crime scenes to detect latent bloodstains on surfaces that have been cleaned?